Welcome to Journal of Theoretical and Applied Information Technology

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This paper presents the results of a newly developed hybrid Simulated Annealing –Direct search Algorithm (SADS) for the optimization of mechanism synthesis for function generation problem and proposes a hybrid optimization method based on the fusion of the Simulated annealing (SA) and Rosenbrock Search (RS), derivative-free type method of optimization, in which the SA is embedded the RS to enhance its search capability. This algorithm combines the advantages of the global optimization technique and a classical non linear programming technique. A brief overview of hybrid SADS algorithm is presented and applied to dimensional synthesis of a planer four bar mechanism. The optimization is carried out to minimize the objective function formulated from the structural error at the accuracy points. A novel hybrid SADS is employed to determine the optimal values for the design variables that best satisfy the desired objectives of the problem. Simulation results demonstrate the remarkable advantages of our approach in achieving the diverse optimal solutions and improved converge speed. The applicability of this algorithm is illustrated by solving a nonlinear function generation problems and the method produce accurate and acceptable solution in all cases.

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Fading problem is a major impairment of the wireless communication channel. To mitigate the fading problem and to have reliable communications in wireless channel, channel coding technique is often employed. In this paper the BER (Bit Error Rate) performances is shown from analytically and by means of simulation for Rayleigh fading multipath channels. Here the convolution code is used as a channel coding technique. The performance of convolution encoded binary phase shift keying (coded BPSK) with coherent
detection and Viterbi decoding is investigated. Obviously the performance of coded signal in terms of BER is better than uncoded signal and in this research; the main focus is to investigate how much improvements of BER is occurred using convolution code with BPSK for Rayleigh fading channel. The simulation results are shown here graphically.

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This paper deals with modeling and simulation of Voltage Source Inverter based STATCOM using Push-Pull inverter. The eight bus system is modeled and simulated using sim power system block set. Creation of voltage sag and compensation using STATCOM in eight bus system are presented. The present work proposes push-pull inverter for the control of STATCOM.The comparison of multi bus System with and without STATCOM is also presented.

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Turbo codes offer extraordinary performance, especially at low signal to noise ratio, due to a low multiplicity of low weight code words. The interleaver design is critical in order to realize an apparent randomness of the code, thus further enhancing its performance especially for short block frames. This paper presents a new algorithm of obtaining a code matched interleaver leading to very high minimum distance and performances. The design method is described in depth, and the simulation results are plotted against the Long Term Evolution (LTE) standard interleaver.

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Importance of a software system is due to its inner data and databases and not to its codes. Therefore, with the appearance of new software, converting data of the previous systems to the new ones is significant and plays an important role in organizations. Although this conversion process may have different phases but the first phase is under consideration in this paper. First phase in the process of converting data, which refers to assessing tables and finding equivalent fields in both legacy and modern databases is being called
matching metadata. Considering its’ importance, this paper provides an automatic and intelligent method for assessing table and equivalent fields in both databases and for extracting the degree of their accordance. Then, the proposed method will be evaluated on sample databases and the consequent results will be presented.

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Conventional boost PFC converter suffers from the high conduction loss in the input rectifier-bridge. Higher efficiency can be achieved by using the bridgeless boost topology. In this paper, digital simulation of bridgeless PFC boost rectifiers, also called dual boost PFC rectifiers, is presented. Performance comparison between the conventional PFC boost rectifier and the bridgeless PFC boost rectifier is performed. A Closed loop controlled bridgeless PFC converter is modeled and simulated.

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Load forecasting is an important component for energy management system. Precise load forecasting helps the electric utility to make unit commitment decisions including decisions on purchasing and generating electric power, load switching, and infrastructure development. Besides playing a key role in reducing the generation cost, it is also essential to the reliability of power systems. Short-term load forecasting (STLF) can help to estimate load flows and to make decisions that can prevent overloading. Timely implementations of such decisions lead to the improvement of network reliability and to the reduced occurrences of equipment failures and blackouts. Load forecasting is also important for contract evaluations and evaluations of various sophisticated financial products on energy pricing offered by the market. In the deregulated economy, decisions on capital expenditures based on long-term forecasting are also more important than in a non-deregulated economy where a rate increase could be justified by capital expenditure projects. Data mining plays the key role to infer the information which is important to make the right decision. In this article we examine and analyze the use of genetic algorithm (GA) techniques for the determination of weights in a back propagation network (BPN) for short-term load forecasting.

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This paper presents a novel design of a Takagi-Sugeno fuzzy logic control scheme for controlling some of the parameters, such as speed, torque, flux, voltage, etc. of the induction motor. Induction motors are characterized by highly non-linear, complex and time-varying dynamics and inaccessibility of some of the states and outputs for measurements, and hence it can be considered as a challenging engineering problem. The development of advanced control techniques has partially solved induction motor’s speed control problems; because they are sensitive to drive parameter variations and the performance may deteriorate if conventional controllers are used. Fuzzy logic based controllers are considered as potential candidates for such an application. Further, the Takagi-Sugeno control strategy coupled with rule based approach in a fuzzy system when employed to the induction motor yields excellent results compared to the other methods as this becomes a hybrid & integrated method of approach. Such a mixed implementation leads to a more effective control design with improved system performance, cost-effectiveness, efficiency, dynamism, & reliability. The closed loop speed control of the induction motor using the above technique thus provides a reasonable degree of accuracy which can be observed from the results depicted at the end. Simulink based block model of induction motor drive is used for the simulation purposes & its performance is thereby evaluated for the speed control. The simulation results presented in this paper show the effectiveness of the method developed & have got a wide number of advantages in the industrial sector & can be converted into a real time application using some interfacing cards.

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This paper deals with simulation of input parallel, output series QRC fed DC servo drive. The salient feature of QRC is that the switching devices can be either switched on at zero voltage or switched off at zero current, so that switching losses are zero ideally. Switching stresses are low, volumes are low and the power density is high. This property imparts high efficiency and high power density to the converters. The output of QRC is regulated by varying the switching frequency of the converter. Hence it is called Frequency modulated Zero current/zero voltage switching quasi resonant converter. Simulation results show that the ZCS-QRC’s have low total harmonic distortion. Input parallel output series QRC fed DC servo drive is simulated and the results are presented. This converter is proposed for DC servo motors with higher voltage rating.

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In cellular networks, quantities such as number of handoff probability and handoff rate are very important parameters in the cellular system performance analysis. In previous literature, several techniques were introduced to evaluate these parameters; however, there are some limitations in the introduced techniques. In this paper, we approximate number of handoff probability and handoff rate in cellular systems in which the call holding time and cell residence time follow arbitrary statistical distributions. Specifically, we derive approximate expressions to evaluate the probability mass function of handoff number and handoff rate. The technique used does not require knowledge of the distribution of the cell residence times but only their first two moments, which may be determined easily from empirical data. The analytical results are validated by computer simulation.